A cytokine that attracts white blood cells (WBCs). These secreted proteins regulate the migration of WBCs from the blood into the tissues and promote inflammation. Some are also essential for proper embryonic development. Over 40 different chemokines have been identified. [some examples]

Places in a single strand of DNA where the sequence is 5' Cytosine-phosphate-Guanine 3'. In vertebrates, this sequence occurs less often than would be expected by chance. However, CpG sites are found at higher frequency in some regions of the genome called CpG islands. CpG islands are often found close to gene promoters and may affect the level of gene transcription.